Life expectancy still not used to determine aggressiveness of prostate cancer treatment

More than half of prostate cancer patients age 66 years and older have life expectancies of less than 10 years, yet half of them were over-treated for their prostate cancer with surgery, radiation, or brachytherapy. This is according to the first study to rigorously address prostate cancer treatment trends by life expectancy in a large, nationally representative sample.

National guidelines recommend that men with low- and intermediate-risk prostate cancer and life expectancies of less than 10 years should not be treated with radiation or surgery, since they are unlikely to live long enough to benefit from treatment.

Randomized controlled studies have suggested that it takes 10 years for significant differences in survival to develop between watchful waiting, which is monitoring the cancer closely but not treating it, and aggressive therapies. It only makes sense to not treat men expected to die of something else within 10 years.

But the researchers found that men were being treated aggressively anyway, with little regard for their quality of life, said study first author Timothy Daskivich, MD, of the University of California Los Angeles (UCLA). The study was published in Cancer (2014; doi:10.1002/cncr.28926).

“Life expectancy is poorly integrated into treatment decision-making for prostate cancer, yet it is one of the primary determinants of whether a patient will benefit from treatment with surgery or radiation,” Daskivich said. “Because these treatments have side effects such as erectile dysfunction, urinary incontinence, and bowel problems, it's critical for men with limited life expectancies to avoid unnecessary treatment for low- and intermediate-risk prostate cancer.”

Researchers sampled 96,032 men age 66 years and older with early stage prostate cancer diagnosed during 1991 to 2007 from the Surveillance, Epidemiology, and End Results (SEER) Medicare database. They calculated life expectancy using the patient's age and other medical conditions at diagnosis and then determined treatment patterns in those men whose life expectancies were less than 10 years.

The research team found that men, ages 66 to 69 years, with life expectancies of less than 10 years based on their health status were treated aggressively with radiation, surgery, or brachytherapy 68% of the time.

In men with life expectancies of less than 10 years, those ages 70 to 74 years underwent aggressive treatment 69% of the time; those ages 75 to 79 years, 57% of the time; and men 80 years and older were treated aggressively 24% of the time.

“Describing treatment trends by both age and health status is key, because younger, sicker men may have life expectancies of less than 10 years, while older, healthier men may have life expectancies longer than 10 years,” Daskivich said.

“We observed that greater than half of men age 66 years and older had life expectancies of less than 10 years and that nearly half of those received aggressive treatment, mostly with radiation therapy,” the study states. “Because of their low likelihood of 10-year survival, these men are unlikely to live long enough to substantially benefit from aggressive treatment, but they still incur its associated side effects and financial burden. We hope that this information will promote greater awareness of the role of life expectancy in treatment decision-making for men with low- and intermediate-risk disease.”